Ice cores are cylinders of ice drilled out of an ice sheet or glacier. Most ice core records come from Antarctica and Greenland, and the longest ice cores extend to 3km in depth. The oldest continuous ice core records to date extend 123,000 years in Greenland and 800,000 years in Antarctica. Ice cores contain information about past temperature, and about many other aspects of the environment. Crucially, the ice encloses small bubbles of air that contain a sample of the atmosphere — from these it is possible to measure directly the past concentration of gases (including carbon dioxide and methane) in the atmosphere.
and do we have an answer for the official age of the earth and how it relates to a small sample size of avg temp's due to just barely over a 100 yrs of data?
come on guys. i know you can nail this one.
Antarctic ice cores show us that the concentration of CO2
was stable over the last millennium until the early 19th century. It then started to rise, and its concentration is now nearly 40% higher than it was before the industrial revolution (see Fig. 2). Other measurements (e.g. isotopic data) confirm that the increase must be due to emissions of CO2
from fossil fuel usage and deforestation. Measurements from older ice cores (discussed below) confirm that both the magnitude and rate of the recent increase are almost certainly unprecedented over the last 800,000 years. http://www.antarctic...orebriefing.php